#  File src/library/stats/R/ppoints.R
#  Part of the R package, http://www.R-project.org
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  A copy of the GNU General Public License is available at
#  http://www.r-project.org/Licenses/

ppoints <- function (n, a = ifelse(n <= 10, 3/8, 1/2))
{
    if(length(n) > 1) n <- length(n)
    if(n > 0)
	(1L:n - a)/(n + 1-2*a)
    else numeric(0L)
}
